The present invention relates to a resecting device and method for excision and removal of tissue from a patient's body and, more particularly, to a resecting cannula formed with resecting teeth and a hollow, and provided with rotary motion, such that when operated to rotate and contacted with a tissue, the tissue is excised into, and retained within, the hollow of the cannula. In addition, the device in accordance with prefenred embodiments of the teachings of the present invention is provided with a heating device, such that blood homeostasis can be effected, and/or with a dedicated mechanism for collecting the resected tissue for later analysis.
Modem surgical procedures have been utilized by the medical field for decades to diagnose and repair a variety of conditions. Due to the high risk associated with the highly invasive techniques utilized by surgical procedures, the medical field has adapted procedures and devices which utilize minimally invasive techniques. As such, these devices are designed to effect treatment to various body regions through minimal invasion and trauma to the patient's body.
Furthermore, when required, such devices can also be employed to collect tissue specimen from the region of treatment. For example, by utilizing such devices, tissue excision and collection from a patient's body of, for example, tumorous tissue can be effected, such that the tissue removed is collected and examined.
Further examples of procedures utilizing such devices include removal of the prostate in urological procedures, removal of the ovaries and lesions in gynecological procedures, removal of the gallbladder and kidney/gall stones in gastrointestinal procedures, removal of plaques in cardiovascular procedures, and ophthalmologic procedures for treatment of cataracts.
As such, various tissue removal devices and systems such as resectors and rasps have been devised within the last decade to perform diseconomy procedures.
One such device is employed in the field of neurosurgery, and is used specifically for the removal of tumors, blood clots, lesions, aneurysms or membranes. This device is described in U.S. Reissue Pat. No. 33,258 to Onik. According to Onik, tissue to be removed is drawn by suction into a central bore of an outer cutting sleeve. A pneumatically driven inner cutting sleeve operates as a guillotine to resect the tissue. The tissue is suspended in a saline irrigation fluid which also assists in aspiration of the resected tissue through the inner cutting sleeve.
Another example of a resecting device is disclosed in U.S. Pat. No. 5,643,304 to Schechter. This device includes a reciprocating blade which employs an adjustable reciprocating frequency, such that the frequency employed by the device can be tuned to match the target tissue(s).
While the experiences with this and other similar devices for percutaneous diseconomy have been favorable, there is naturally room for improvements in devices and methods for minimally invasive tissue removal.
The procedures using these devices are less invasive than prior surgical techniques, but there is still a need to reduce the amount of time required to perform the procedures and similar surgeries. Faster tissue removal translates to quicker procedures, reduced invasion and as such a reduced risk of trauma. In addition, as with any procedure involving body tissue excision employing prior art devices, there remains a risk of resecting desirable tissue as opposed to undesirable tissue sought to be removed. Finally, although all surgical techniques involve some trauma to surrounding tissue, there is a clear need to reduce even further the amount of trauma associated with such procedures.
At present, tissue removal devices which generally involve the use of motorized pneumatically driven guillotine, reciprocating blade, or rotary type cutters suffer from several shortcomings. One problem characteristic of these devices is that tissue is often torn, rather than sliced cleanly. In addition, with rotary cutters currently employed, the tissue has a tendency to become "spooled" or wound around the cutter or its drive shaft, thereby clogging or stalling the cutter.
Furthermore, with guillotine or reciprocating blade cutters accurate tissue removal of small tumorous tissue, or alternatively, rapid tissue removal of large tumor masses cannot be effected efficiently.
In addition, cannulas possessing either guillotine or reciprocating blade cutter mechanisms can only excise tissue of a shape resectable by such cutting blade mechanisms, and as such, these devices are implementable within a narrow range of resection applications.
Finally, currently employed resection devices are not provided with a built-in heating device effective in blood homeostasis, even though resection of vascularized tissues can cause a great deal of hemorrhaging, As such, the above mentioned features of the prior art devices lead to inherent limitations which impede such devices from effecting a rapid and accurate removal of various tissue types.
There is thus a widely recognized need for, and it would be highly advantageous to have, a tissue resecting device devoid of the above limitations.